Polygon to binary mask

I've made a polygon using shapely.geometry, then put it into a geopandas dataframe. I've made an array with the same size as the polygon zone

How can I turn this polygon into a binary mask, so I can shape my array as a polygon too?

Thanks for your time.

Solution

I figured it out. Not the most efficient method but it worked.

First I make a mask on the grid, with False on data that is not in the polygon (using contains method). Second I multiply the array by that mask, then take 0 as NaNs.

Here is an example of my code :

# g is anarray with flatten x y coordinates
g = np.stack([
        xi.flatten(),
        yi.flatten(),]) 

# Function to check if in polygon, return bool
def func1d(row, args):
    return args.contains(Point(row[1], row[0]))

# Take mask array and apply along axis, poly is the polygon that we want to use
mask = np.apply_along_axis(func1d, 1, g, args=poly)
g[:,2] = g[:,2]*mask
g[g==0]=[np.NaN] # get 0 be nans (should be a better way to do this but was ok here)
output = g[~np.isnan(g).any(axis=1)] # filter to only save the polygon data